obscurantism.noun
a practice of withholding information from the public (governments concocting.policies of subservience for control of and less freedom for citizens - creeping communism); the policy of preventing facts or full details of something from becoming known through control of information distribution and media presentation
obscurant, obscurantist.nouns
a person or thing that obscures

obscure.adjective
not clear or distinct; ambiguous; hidden; dim; dark; murky
obscure applies to that which is perceived with difficulty, either because it is veiled, perhaps by design – obscurantism

obscure, obscurer, obscurest.adjectives
not readily understood or clearly expressed, mysterious, remote, secluded; deficient in light; dark; so faintly perceptible as to lack clear delineation; indistinct; far from centers of human population (an obscure village); out of sight; hidden (an obscure retreat); ambiguous

obscure, obscured, obscuring, obscures.transitive verbs
to make dim or indistinct (smog obscured our view); block; to conceal in obscurity; hide
obscurely.adverb
obscureness.noun
obscurity.noun,.plural.obscurities
deficiency or absence of light; darkness; the quality or condition of being unknown

occur, occurred, occurring, occurs.intransitive verbs
to take place; come about; happen; to be found to exist or appear (heavy rains occur during a summer monsoon); to come to mind (the idea never occurred to me)

occurrence.noun
an event; incident; a general word for anything that happens or takes place

ornithology.noun
the branch of zoology dealing with birds
ornithological.adjective
ornithologist.noun
a scientist in this branch of zoology

omen.noun
an occurrence or phenomenon believed to portend a future event, either good or bad 
synonyms.portent, sign, warning, premonition, foreboding, augury, indication 

ominous.adjective
threatening; containing a warning of something evil or bad that will happen 
synonyms.menacing, sinister, portentous, threatening (ominous rumblings of discontent; ominous black clouds); inauspicious, foreboding, fateful, unpromising
ominously.adverb
ominousness.noun

opaque.adjective
impenetrable by light; neither transparent nor translucent
opaquely.adverb
opaqueness.noun

opacity.noun,.plural.opacities
the quality or state of being opaque; something opaque; obscurity; impenetrability; dullness of mind

oxide.noun
a binary (two parts; twofold) compound of oxygen with a more electropositive element or group
oxidant.noun
a substance used as an oxidizing agent
oxidation.noun
the process of oxidizing 
oxidize, oxidized, oxidizing, oxidizes-(or, ise).transitive verbs
to combine with oxygen; make into an oxide; to make rusty
Chemistry.–.to increase the positive charge or valence of (an element) by removing electrons
oxidizable (or, isable)-adjective

oxidization (or, isation), oxidizer.nouns
oxidic.adjective

obtain, obtained, obtaining, obtains.transitive verbs
to succeed in gaining possession of as the result of something (astute planning resulted in an enduring endeavor); acquire
intransitive verb use.to be established, accepted, or customary; to succeed
obtainable.adjective
obtainer.noun

obtuse.adjective
mentally slow or emotionally insensitive; dull; stupid
obtuseness.noun
obtusely.adverb

obviate, obviated, obviating, obviates-transitive verbs
to do away with; to attempt to do away with; counter; prevent; render unnecessary; to anticipate and dispose of effectively; render unnecessary
obviation, obviator, obviation-nouns

onslaught-noun
a violent attack

orient, oriented, orienting, orients.transitive verbs
to make familiar with or adjusted to facts, principles, or a situation; to determine the bearings of; to focus (the content of a story or film, for example) toward the concerns and interests of a specific group; to locate, align or place in a particular relation to the points of the compass (orient the swimming pool north and south), or to some reference point
orientation-noun
the act of orienting or the state of being oriented

opinion.noun
a belief or conclusion held with confidence but not substantiated by positive knowledge or proof; what one thinks of something (medical opinion); aan estimation of the merit of a person or thing (has a low opinion of 'greedco's'); the prevailing view (public opinion)

opine, opined, opining, opines.transitive verbs
to hold or state as an opinion

origin.noun
the point at which something comes into existence or from which it derives or is derived (origin of humanity); the fact of originating; rise or derivation
Mathematics.-.the point of intersection of coordinate.axes, as in the Cartesian coordinate system

originate, originated, originating, originates.verbs
transitive verb use.to bring into being; create (Nikola Tesla originated the system of free energy)
intransitive verb use.to come into being; start; stem
origination.noun
originative.adjective
originatively.adverb
originator.noun

originally.adverb
with reference to origin.(mankind originally had no money); at first (what I had originally expected); in a highly distinctive.manner.(interpreted the flute solo most originally)

orbit.noun
a range of activity, experience, or knowledge; a range of control or influence; range; the path of a celestial body or an artificial satellite as it revolves around another body; one complete revolution of such a body; the path of a body in a field of force surrounding another body, for example, the movement of an atomic.electron in relation to a nucleus
orbit, orbited, orbiting, orbits-transitive verb
to put into an orbit (orbit a satellite); to revolve around, such as a center of attraction (the moon orbits Earth)
intransitive verb use.to move in an orbit

orbitals.(atomic orbitals are mathematical descriptions of where the electrons in an atom {or molecule} are most likely to be found); "Experimental data has been the impetus behind the creation and dismissal of physical models of the atom; Rutherford's model, in which electrons move around a tightly packed, positively charged nucleus, successfully explained the results of scattering experiments, but was unable to explain discrete.atomic.emission, that is, why atoms emit only certain wavelengths of light.

"Bohr began with Rutherford's model, but then postulated further that electrons can only move in certain quantized orbits; this model was able to explain certain qualities of discrete emission for hydrogen, but failed completely for other elements. 

"Schrödinger's model, in which electrons are described not by the paths they take but by the regions where they are most likely to be found, can explain certain qualities of emission spectra for all elements; however, further refinements of the model, made throughout the 20th century, have been needed to explain all observable spectral phenomenon.

"Atomic orbitals are mathematical descriptions of where the electrons in an atom (or molecule) are most likely to be found. These descriptions are obtained by solving an equation known as the Schrödinger equation, which expresses our knowledge of the atomic world. As the angular momentum and energy of an electron increases, it tends to reside in differently shaped orbitals. The orbitals corresponding to the three lowest energy states are s, p, and d, respectively. A spatial distribution of electrons occurs within these orbitals. Form is about spatial structure.

"The fundamental nature of electrons prevents more than two from ever being in the same orbital. The overall distribution of electrons in an atom is the sum of many such compositions. This description has been confirmed by many experiments in chemistry and physics, including an actual picture of a p-orbital made by a Scanning Tunneling Microscope."."Models of the Atom," Microsoft® Encarta® Encyclopedia 99